Free Health Calculators — BMI, Calories, TDEE & Sleep

BMI = weight (kg) / height (m)². For pounds and inches, BMI = (weight × 703) / height². The BMI calculator on this page shows the equation, the WHO category bands (underweight < 18.5, normal 18.5–24.9, overweight 25–29.9, obese ≥ 30), and the standard caveats — BMI doesn't distinguish muscle from fat, so athletes often read high.

Start with BMR via Mifflin–St Jeor, multiply by an activity factor (1.2 sedentary → 1.9 very active) to get TDEE, then add or subtract ~500 kcal/day for ~1 lb/week gain or loss. The Calorie and TDEE calculators below run all three steps and show the formula.

TDEE — Total Daily Energy Expenditure — is the number of calories you burn in a typical day, including basal metabolism, activity, and digestion. It's the right baseline for cutting, bulking, or maintaining; eating below TDEE drives loss, above drives gain.

No. They use standard population formulas and are great for self-tracking and goal-setting, but BMR, BMI, and TDEE are estimates that can be off for athletes, older adults, and people with metabolic conditions. Use them as a starting point, not a diagnosis.